36
Serotine Eptesicus serotinus (Schreber 1774)
Three new summer colonies of this declining species were found during 1998. The first was in
a house (now threatened by improvement plans) in Hornchurch: it held around six bats and is
clearly vulnerable. The second was at a house in Fairstead on 14th August, that had been
sprayed with permethrin for furniture beetle some two years earlier; many droppings were
present, together with one bat (which was visible in the ridge). Finally, a number of recent
droppings - indicative of another new roost - were discovered in November during a roof survey
in Manningtree. This unexpected occurrence constituted a new 10km square record.
Leisler's bat Nyctalus leisleri (Kuhl 1818)
Colony counts were conducted as they had been in previous summers, with evidence of a
decline of around 70% during the last decade at both Aveley and Coggeshall.
_________Aveley Coggeshall______Lillie Hallingbury______Danbury Bicknacre
1988 41 
1989 58_______________________________________________________________
1990 62_______________________________________________________________
1991 51__________67___________________________________________________
1992 42__________69_________________________________59________________
1993 61__________61_____________________________________________17
1994 37__________39_____________________________________________15
1995 31__________25_____________________________________________12
1996 26__________31________________59_________________________________
1997 29__________22________________50___________________________23
1998 24 18 52 7
The last record of the year was of a male found at Billericay on the surprisingly late date of 29th
December. It was released the following day.
Brown long-eared bat Plecotus auritus (L, 1758)
Two new 10km square records were recorded in 1998. On both occasions the species was
identified by the presence of droppngs. The first example concerned a barn conversion at
Clavering (TL43) and the second was a house roof at Little Chesterford (TL54). Other records
of interest were of an individual found in the passenger terminal at Stansted Airport, another
observed at night in a toilet block at Cudmore Grove Country Park (!) and a third found in the
Essex Wildlife Trust Visitor Centre at Thorndon Park.
Essex Naturalist (New Series) 16 (1999)